Status

of the

Front End Test Stand

April 2007

Infrastructure

• R8 refurbished

• Laser lab under construction

• Vacuum system for first section delivered

• Stands for accelerator ordered

• Basic electronic equipment for first phase delivered

Extensive experimental program underway on the IS rig. Main goal is the reduction of the source emittance by roughly a factor of 3.

57 mm

Ion source development

Ion source – transversal density distributionas a function of extraction potential

5 kV Ext 5.5 kV Ext 6 kV Ext 6.5 kV Ext

7 kV Ext 8 kV Ext 9 kV Ext 11 kV Ext

LEBT- 1st vacuum vessel design

LEBTInitial beam distribution based on pepper-pot data

At end of LEBT

rms norm ~ 0.9 mm mrad

1% beam loss

Universidad del Pais Vasco joined the collaboration =>

responsible for LEBT (in cooperation with Warwick) & beam dump

3D model of B-fields incorporated into simulations => slight increase in field strength required.

RFQ cold model

The quality of the quadrants will be controlled by using a CMM and beat pull measurements will be performed before and after brazing.

The 4 quadrants of the 4 vane RFQ cold model (l=0.5 m) are machined.

First RF measurements on the unbrazed RFQ cold model

First tests of the cold model using new couplers showed a resonant frequency of ~ 323 MHz

A very good field flatness has been

measured using the beat pull method

MEBT and ChopperMEBT & Chopper:

-Transition from particle trajectory design to real design

- Incorporation of pumping ports etc. into design and reoptimisation of beam dynamics

Hybrid quadrupoles:

- The printed circuit electromagnet: A company near Newbury specialised in printed circuit boards manufacturing. In progress.

- Daresbury Magnet Testing Group agreed to measure the PMQ in the next month. (Point by point measurement with a Hall probe).

Particle dynamics:

- Comparison between CERN and RAL design (IS to end of DTL) showed slightly better results for RAL solution - simulations with higher current are planned.

- Code benchmarking in progress

MEBT & Chopper – code benchmarking

TraceWin/Partran

GPT

Lattice: FETS Scheme A Codes: TraceWin/Partran, Trace3D, GPT

Pepper pot emittance measuring device

Close up of the assembled grid head showing the quartz plate.

The grid head is mounted to the

cooled rod.

The linear shift mechanism mounted to the main flange.

Adjustable camera mount.

Cooled feed through rod.

Tungsten screen

Copper block Scintillator screen

H- Beamlets

Fast CCD CameraH- Ion Beam

A pepper pot device mounted on a linear stage for correlated measurements of the transversal phase space along beam propagation will be available soon.

Pepperpot data analyses test

Camera res. = 49 microns/pixel Angle res. = 4.88 mrad

Image width: 100mmx-x’

y-y’

Laser tomography

Motion controller

Rotary stage

Amplifiers and

power supplies

Linear stage

Encoders

Laser emittance

negative ions,RG neutrals

phot

o de

tach

edne

utra

ls

deflected negative ions

R=477.5mmArc length 500mm

B = 0.522TGap 136mm

Width 200mmDeflection 60deg

max. beam size ~R=20mm

At the position of photoninteraction can be detected

a max. beam diameterof 40mm with +/-30mrad(a matched ion beam has

app. 20mm and +/-20mrad).

Laser emittancePhotodetachment Diagnostic Dipole (FETS)

D:\FETS\MAGNET\POISSON-SIMULATIONEN\H-MAGNET\UEBUNG@UNI\VERS-E_YOKE+COIL VARIATION\DIPOLE016.AM 2-12-2007 18:55:56

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good field region20cm

4cm15cm

vacu

umve

ssel

space for piezo driven stages

Summary & outlook

• Very good progress on all fields

• IS optimisation is a major physical challenge but

first results are encouraging

• RFQ cold model pre tests started

• Infrastructure for first phase prepared

• Good collaboration with Spanish partners